Imagine a world where years are not numbered. Would you know, or be able to explain how old you are? Could you imagine how long it will be before your future grandchildren could take over your job? How would you tell your community's history to someone from another culture? That's the way the ancient world was. Each culture had a different way of explaining when something happened.

In ancient Mesopotamia, years could be designated by an outstanding event of the preceding 12 months: something could be said to happen, for instance, in the year when king Naram-Sin reached the sources of the Tigris and Euphrates river, or when king Enlil-bani made for the god Ninurta three very large copper statues. Alternatively, events could be dated by giving the name of the holder of an annual office of state: something happened in the year when two named Romans were consuls, or when an elite Athenian was chief magistrate, and so on. Finally, and most commonly in the kingdoms of antiquity, events could be dated by counting the throne year of the monarch: the fifth year of Alexander the Great, the 40th year of king Nebuchadnezzar II, and so on.

Each of these systems was geographically localised. There was no transcendent or translocal system for locating oneself in the flow of history. How could one synchronise events at geographical distance, or between states?

You have to admit that our system of assigning year numbers that don't reset is much handier for understanding history, for planning the future, and for communicating. So how did that start? Hint- it was a long time before the BC/AD system was introduced. Read how the first universal linear year numbering system began at Aeon. -via Digg